Preheat oven to 350°F (177°C). Grease three 8-inch round cake pans, line with parchment paper rounds, then grease the parchment paper. Parchment paper helps the cakes seamlessly release from the pans. (If it’s helpful, see this parchment paper rounds for cakes video & post.)

Using a handheld or stand mixer with a paddle attachment, beat the butter on high until smooth and creamy, about 1 minute. Add granulated and brown sugars and beat on medium-high speed until combined, about 2 minutes. (Here’s a helpful tutorial if you need guidance on how to cream butter and sugar.) Add the oil and beat until combined and light and creamy, about 3 more minutes. Add the eggs and vanilla, and beat on medium speed until everything is completely combined, about 1 minute. Scrape down the sides and bottom of the bowl as needed.

In a large bowl, whisk together the flour, baking powder, baking soda, and salt. Add the dry ingredients to the wet ingredients. Beat on low speed for a few seconds, then beat in the milk, lemon zest, and lemon juice *just* until combined. Toss the blueberries with 1 Tablespoon of flour and gently fold into the batter. Batter is thick. Do not over-mix.

Spoon batter evenly into prepared cake pans. Bake for about 22–26 minutes or until a toothpick inserted in the center comes out clean. Remove from the oven and allow to cool completely in the pan before assembling and frosting.

Using a handheld or stand mixer with a paddle attachment, beat cream cheese and butter together on medium speed until no lumps remain, about 3 full minutes. Add confectioners’ sugar, heavy cream, vanilla extract, and salt with the mixer running on low. Turn mixer up to high speed and beat for 3 minutes.

(Note: See my how to assemble and decorate a layer cake video & tutorial if you want extra help with this step.) First, using a large serrated knife, slice a thin layer off the tops of the cakes to create a flat surface. Place 1 layer on your cake stand. Evenly cover the top with cream cheese frosting. Top with 2nd layer, more frosting, then the third layer. Top with frosting and spread around the sides. The recipe doesn’t make a ton of frosting, just enough for a light frost. Top with blueberries or lemon garnish if desired. Refrigerate for at least 45 minutes before cutting or else the cake may fall apart as you cut.

Cover leftover cake tightly and store in the refrigerator for up to 5 days. I like to use a cake carrier for storing and transporting.